Shuup

- Testing: add missing migrations

- CMS: add missing migrations

Changed

- Removed Django 1.11 compatible code from the code base

Fixed

- Admin: fix logout view that was loading the template from Django instead of custom template
- Admin: return `None` when the order source was not correctly initialized in JsonOrderCreator
- Core: add parameter in shuup_static to load the version of a given package

- Add initial support for Django 2.2

- Fix issue on arranging menu after reset which sets the configuration None
which in the other hand is hard to update as it is not dict.

- Admin: add option to arrange menu for superuses, staff and suppliers

For now it was only possible to arrange menu per user which is not
sufficient while the menu needs to be arranged for the whole group
of people like shop staff or vendors.

Allow to create menu custom menu for superusers, staff or suppliers,
but remain the possibility to still arrange the menu per user.

Add option to translate each menu arranged for these groups since
not all vendors/suppliers necessary speak same language.